An evolutionary approach to develop durable disease resistance to bacterial canker of cherry

一种进化方法来培养对樱桃细菌性溃疡病的持久抗病性

• 批准号: BB/P006272/1
• 负责人: Richard Harrison
• 金额: $ 75.46万
• 依托单位: National Institute of Agricultural Botany
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FP006272%2F1
• 关键词: evolutionary; approach; develop; durable; disease

The resurgence of cherry production in the UK from 400 tonnes in the year 2000 to 3500 tonnes in 2014, achieved through the adoption of high-density plantings, has led to bacterial canker, which is caused by Pseudomonas syringae, becoming the main disease of cherry, for which there is no effective control. Our recent work has shown that bacterial canker is not caused by a single bacterial population but by three distinct groups of Pseudomonas, each having independently acquired the ability to cause disease on cherry and each manipulating the host in subtly different ways in order to subvert plant defences and survive in long term associations with the tree. This phenomenon is termed convergent evolution and is an interesting finding, as from it several fundamental scientific questions arise. In this proposal we seek to answer four questions, based upon recent research into this commercially important, yet understudied, pathogen. First, what is the basis of niche survival and persistence of P. syringae on cherry? We wish to understand if different complements of toxins, effectors (a special class of proteins secreted by the pathogen that are involved in suppressing plant immunity and promoting pathogen growth) and other gene clusters, implicated in manipulation of host defences, determine survivability in particular niches (in woody tissues for example) or at particular times of year, and whether these are different in our three Pseudomonas clades? Second, how is host specificity determined by effector content? Do conserved effectors, over-represented in convergently evolved Pseudomonas groups when compared to closely related non-cherry or plum pathogens, play an essential role in adaptation onto these hosts? This evolutionary approach, integrating information from many different strains of Pseudomonas is a novel way of utilising patterns of molecular evolution to provide insights into which pathogen genes are important targets for further study. Addressing these two questions will provide fundamental insights into how pathogens evolve onto their hosts and may provide new avenues to pursue when considering how to control these pathogens in the field. Third, which effectors control known resistance responses in cherry? This is a crucial question. Part of the plant immune system is controlled by specific classes of genes (broadly termed resistance or R genes) that have evolved to encode proteins that recognise pathogen attack, by monitoring for the presence or activity of effectors and then rapidly activating plant defence responses. Effectors are often referred to as the pathogen's Achilles heel, as they are both required for pathogenicity but leave the pathogen vulnerable to detection. Understanding which effectors are recognised in cherry material is important to predict the likely usefulness of particular plant resistances. For example, recognition of a rare effector at low frequencies in a pathogen population is less useful than an R gene that recognises a highly conserved effector, essential for pathogenicity. Our approach seeks to identify resistance genes that target effectors that are common to all strains of cherry infecting Pseudomonas, as well as other previously identified, but uncharacterised, resistances. Fourthly, what is the genetic architecture of resistance to P. syringae in cherry? By identifying the regions of the cherry genome that control resistance, using a technique called genetic mapping, molecular markers tagging R genes can be developed and used by the UK industry (plant breeders) in order to breed cherry cultivars resistant to all three groups of pathogenic Pseudomonas.Answering these questions provides plant breeders with the information that they require to develop resistant cultivars, improving yield, quality and the profitability of the industry and reducing waste in the supply chain.

通过采用高密度种植，英国樱桃产量从2000年的400吨回升至2014年的3500吨，导致由丁香假单胞菌引起的细菌溃烂成为樱桃的主要病害，目前尚无有效的防治措施。我们最近的工作表明，细菌溃烂不是由单一的细菌种群引起的，而是由三组不同的假单胞菌引起的，每一组假单胞菌都独立地获得了在樱桃上致病的能力，并且每一组都以微妙的不同方式操纵宿主，以破坏植物的防御并与树长期结合在一起。这种现象被称为收敛进化，这是一个有趣的发现，因为由此产生了几个基本的科学问题。在这个提案中，我们试图回答四个问题，基于对这种具有重要商业意义但未被充分研究的病原体的最新研究。首先，紫丁香叶蜂在樱桃上的生态位生存和持续存在的基础是什么？我们希望了解毒素、效应物(病原体分泌的一种特殊类型的蛋白质，参与抑制植物免疫和促进病原体生长)和其他基因簇的不同补体是否决定了特定生态位(例如，在木质组织中)或一年中的特定时间的存活率，以及它们在我们的三个假单胞菌分支中是否有所不同？第二，效应物的含量如何决定宿主的专一性？与密切相关的非樱桃或李子病原体相比，保守的效应器在汇聚进化的假单胞菌群体中过度表达，在适应这些宿主方面发挥关键作用吗？这种集成了来自许多不同假单胞菌菌株的信息的进化方法是一种利用分子进化模式的新方法，以提供对哪些病原体基因是进一步研究的重要目标的见解。解决这两个问题将提供对病原体如何进化到宿主的基本见解，并可能在考虑如何在实地控制这些病原体时提供新的途径。第三，在樱桃中，哪些效应器控制已知的抗性反应？这是一个至关重要的问题。植物免疫系统的一部分由特定类别的基因(广义上称为抗性或R基因)控制，这些基因已经进化成编码识别病原体攻击的蛋白质，通过监测效应器的存在或活性，然后快速激活植物防御反应。效应器通常被称为病原体的阿喀琉斯之踵，因为它们都是致病性所必需的，但使病原体容易被检测到。了解樱桃材料中识别的效应器对于预测特定植物抗性的可能用处很重要。例如，在病原体群体中识别频率较低的稀有效应器，不如识别高度保守的效应器的R基因那么有用，后者对致病性至关重要。我们的方法试图识别针对感染假单胞菌的所有樱桃菌株共有的效应器的抗性基因，以及其他先前已识别的但未表现出特征的抗药性。第四，樱桃对紫丁香叶枯病菌的抗性遗传结构是什么？通过鉴定樱桃基因组中控制抗性的区域，利用一种称为遗传作图的技术，标记R基因的分子标记可以被英国工业(植物育种者)开发和使用，以培育出对所有三组致病假单胞菌都具有抗性的樱桃品种。回答这些问题为植物育种者提供了培育抗病品种所需的信息，从而提高了产量、质量和产业的盈利能力，并减少了供应链中的浪费。

项目成果

Genomic and functional analysis of phage-mediated horizontal gene transfer in Pseudomonas syringae on the plant surface.

• DOI: 10.1111/nph.18573
• 发表时间: 2023-02
• 期刊: NEW PHYTOLOGIST
• 影响因子: 9.4
• 作者: Hulin, Michelle T.;Rabiey, Mojgan;Zeng, Ziyue;Dieguez, Andrea Vadillo;Bellamy, Sophia;Swift, Phoebe;Mansfield, John W.;Jackson, Robert W.;Harrison, Richard J.
• 通讯作者: Harrison, Richard J.

An improved conjugation method for Pseudomonas syringae.

一种改进的丁香假单胞菌缀合方法。

• DOI: 10.1016/j.mimet.2020.106025
• 发表时间: 2020
• 期刊: Journal of microbiological methods
• 影响因子: 2.2
• 作者: Neale HC

Identifying resistance in wild and ornamental cherry towards bacterial canker caused by Pseudomonas syringae.

• DOI: 10.1111/ppa.13513
• 发表时间: 2022-05
• 期刊: PLANT PATHOLOGY
• 影响因子: 2.7
• 作者: Hulin, Michelle T.;Dieguez, Andrea Vadillo;Cossu, Francesca;Lynn, Samantha;Russell, Karen;Neale, Helen C.;Jackson, Robert W.;Arnold, Dawn L.;Mansfield, John W.;Harrison, Richard J.
• 通讯作者: Harrison, Richard J.

Characterisation of the pathogenicity of strains of Pseudomonas syringae towards cherry and plum

丁香假单胞菌菌株对樱桃和李子的致病性特征

• DOI: 10.1101/227223
• 发表时间: 2017
• 作者: Hulin M

Characterization of the pathogenicity of strains of Pseudomonas syringae towards cherry and plum.

• DOI: 10.1111/ppa.12834
• 发表时间: 2018-06
• 期刊: Plant pathology
• 影响因子: 2.7
• 作者: Hulin MT;Mansfield JW;Brain P;Xu X;Jackson RW;Harrison RJ
• 通讯作者: Harrison RJ